Coal-digging apparatus



(No Model.)

J, W. HBWITT. GOAL DIGGNG APPARATUS.

UNITED STATES PATENT OFFICE.

JOHN W. HEVITT, OF ALLEGHENY, PENNSYLVANIA.

COAL-DIGGING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 341,240, dated May 4,1886.

Application filed Septcmher 2, 1885. Serial Xo. 175,934. (No model.)

To (LZZ whom it may concern,.-

Be it known that I, JOHN WV. HEWITT, a citizen of the United States, anda resident of Allegheny, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inCoal-Digging Apparatus, of which the following is a full, clear, andexact description.

The object of theinvention is to provide means whereby the vein of coalmay be undercut, so that the superposed mass may bel dragged downquickly and at little expense.

In the drawings, Figure l represents a top plan view ofthe apparatus;Fig. 2, a side elevation showing the operating mechanism of therotarycutter; Fig. 3, a side elevation of the opposite side from thatshownin Fig. 2, showing the mechanism for drawing the machine forwardover its track.

Similar letters of reference indicate corre spending parts throughoutthe different views.

A is the track or bed, having preferably at least one of its rails agrooved. The track is divided in two sections, a a2, which are connectedtogether by a pivot-joint in one rail. rlhe object of this constructionis to allow the machine to be worked on short passages, where it wouldbe impossible for the Vfull length of the track or bed to be placed.Upon this track or bed slides the frame B of the machine. Said frame hasupon one side an extension, b, extending laterally for several .feet andin close proximity to the plane of the track. The object of saidextension is to carry the outer extremity of the rotating cutter-bar C.Said bar is secured to extension bby alaterally-swinging bearing, c. Theopposite extremity of said bar is provided with a sliding bearing inframe B.

Secured to the bar C near its sliding bearing is a diagonallycentereddisk, D, whose periphery works in a plate, d, attached to frame B. Theobject of this construetionis togive the bar G,when revolving, alaterally-re ciprocating motion, and thereby cause the cutters to cutover the space occupied by the swinging bearing c.

Secured to the bar C is a chain-wheel, E, about which and about a secondchain-wheel, E, passes a driving-chain, e. The Wheel E is borne by ashaft, whose outer extremity carries a gear-pinion, e. The latter mesheswith a wheel, F, carried by the driving-shaft f. On one extremity ofsaid shaft is a drivingpulley, (or, if preferred, a crank connected withan engine carried by frame B,) and on the other extremityis aneccentric, G. Upon this eccentric works a pit1nan,\H, whose freeextremity is adj ustably secured in a vslotted curved lever, I. The freeextremity of said lever works loosely on a shaft, Zt, and carries apawl, t', which works into the teeth of a ratchet-wheel, K, also carriedby said shaft. A second pawl, Z', secured to frame B,prevents backwardmovement of the shaft. 'i i Attached to the outer extremity of' shaft kis a chain wheel or drum, L, around which passes a chain, Z. rlhe latterpasses from the wheel under a pulley, Z, and thence to the far end ofthe track or bed, where it is secured.

The cutters which are secured to bar C may be of any desired form andarrangement.

The operation of the inventionis as follows: The track or bed is laidalong the side of the seam of coal and the machine placed in position.The chain Z is then secured in place and power applied to the machine.transmitted through the medium of the mechanism already described,causes the revolving cutter-bar to rotate with great velocity,there bycutting away the coal tothe depth of about four feet and to a height ofabout eight inches.

Said power, A

Simultaneously with the revolution of the cutters the eccentric G,through the medium of the pitman H, lever Land itspawhcauses theratchet-wheel, and with it the chain-drum L, to revolve, and thus bymeans of chainZdrags the machine forward over its bed and feeds thecutters to the coal. Vhen the machine has reached the end of the track,the latter is moved forward and the aforegoing operation repeated, andso on. The coal,afterbeing undercut in the aforegoing manner, is draggeddown by the miners with their picks, this being a matter ofcomparatively small trouble, the chief difeultyand the hardest work ofthe miners consisting in the aforesaid undercutting.

Having thus described claim is l. rlhe combination of the frame B,having side extension, b, open front slot, d, the rotary cutter-bar C,and the diagonal disk D on said bar, the bar C being arranged in frontbear- IOC ings. of said frame and extension, as and for point in frontof frame,where itis fastened, as

the purpose specified. and for the purpose set forth.

2. The combination WiththefrztmeB carl T ing the cutter mechanism, ofthe eceehtrior JOHN W HEWITT' 5 on shaft f, the pitman H, the loose andslotted Vitnesses;

aro lever I, the shaft 7c, having paw] 13 and ROBERT HEWITT,ratchet-wheel K, the drum L, and the chain Z, C. SHALER, l passing fromits shaft under a pulley, Z, to a JOHN M. ROBB. l

